Joint hypermobility

How it works

Nobody has double joints. The word describes joints that move further than average¹. In many hypermobile people the ligaments are looser than usual. Differences in collagen, a protein in ligaments, can cause this. It tends to run in families¹.

The standard test is the Beighton score². It has nine points, one for each of these checks:

• Bending each little finger back past 90 degrees (one point per hand).
• Bending each thumb back to touch the forearm (one point per hand).
• Straightening each elbow more than 10 degrees past straight (one point per arm).
• Straightening each knee more than 10 degrees past straight (one point per leg).
• Placing both palms flat on the floor with straight knees (one point).

A score of 5 or more out of 9 is usually counted as hypermobile in adults². Some doctors use 6 for children and 4 for people over 50, because flexibility falls with age⁵⁶.

Most hypermobile people have no symptoms. Some have joint pain, frequent sprains, or dislocations along with the flexibility¹. This may be a sign of hypermobility spectrum disorder. Doctors use that name only when another cause, such as Ehlers-Danlos syndrome, is ruled out¹.

How common it is

The 10% to 25% figure is a rough range, because estimates vary between studies¹⁵. Cutoff scores differ between doctors². Age, sex, ethnicity, and fitness also affect the Beighton score⁵. Flexibility is naturally higher in children and falls with age, which is why some doctors lower the pass score for people over 50². Studies also find hypermobility more common in women and in some ethnic groups, though the reasons are not fully worked out¹⁵. The 3% figure for symptomatic hypermobility comes from one UK population survey. It found 3.3% of women and 0.6% of men affected⁵. Diagnosed hypermobility spectrum disorder and hypermobile Ehlers-Danlos syndrome together are rarer, about 1 in 600 to 1 in 900 people⁵.

Try it

These steps cover five of the nine Beighton checks².

1. Hold one hand flat, palm down. With the other hand, bend the little finger straight back. If it passes 90 degrees, that is one point.
2. Bend your thumb down toward the inside of your forearm. If the thumb touches the forearm, that is one point.
3. Stand with your knees straight and bend forward. If both palms rest flat on the floor, that is one point.
4. Repeat steps 1 and 2 on the other hand. Add the points. The most you can score here is 5, which meets the adult cutoff on its own. A lower score does not rule out hypermobility, because the elbows and knees add four more points².

Is it a problem?

For most people, no. Flexible joints are normal and are useful in dance, gymnastics, and music.

See a doctor if many joints are loose and you also have:

• regular pain,
• joints that slip out of place,
• very stretchy or fragile skin,
• frequent unexplained bruising.

These can point to a connective tissue condition such as Ehlers-Danlos syndrome, which needs a proper assessment³.

History and culture

Contortionists are usually hypermobile and train it further. Groups such as r/ehlersdanlos share advice on living with the symptomatic form⁴.